The present invention is concerned with a gas scrubber of the wet collector type. The invention is concerned with the removal of particles of the micron or sub micron range entrained in a gas stream, preferably air. Gas streams are generally introduced into a liquid spray environment and are passed upwardly through a housing abruptly changing the direction of the gas stream in order to remove the particles entrapped therein. Gas scrubbers of the prior art have been described in such patents as U.S. Pat. Nos. 3,328,009, 3,347,535, 3,624,696, 3,205,641, and 3,581,467.
Many of the prior art apparatus, especially that described in the 641 patent, employ a spray of liquid in order to entrap the particles in the gas. A liquid is pumped onto an impingement surface. This impingement surface rotates by means of a spinner shaft which in turn is connected to a power means. The spinner shaft and its bearings generally are exposed to the environment of the air scrubber which may be either quite corrosive due to the chemical composition of the particles, or quite abrasive, or both. As the particles have a tendency to work themselves into the bearings of the shaft and destroy the bearings, periodically it is required to halt the operation of the gas scrubber in order to replace worn bearings and the like. The down time of the gas scrubber is therefore increased due to need to repair the spinner shaft and the bearings thereof.
It has been found that the down time can be substantially decreased if the bearings supporting the spinner shaft are not only removed from the environment of the gas scrubbing but also disposed in an environment of higher pressure than that where the scrubbing action occurs. It is therefore an object of the present invention to decrease the down time of a gas scrubber.
I have also found that an improvement in the efficiency of the gas scrubbing action may be obtained while at the same time the cost of manufacture and of operation of the gas scrubber can be reduced by eliminating the spinner shaft drive motor, so that the spinner shaft is "free wheeling," and utilizing a liquid diffusing spinner which is driven solely by the impingement of the liquid from the pump discharge against the spinner. Therefor, another object of the invention is to reduce the cost of manufacture and operation of a gas scrubber of the wet collector type without suffering any loss in efficiency, and in fact obtaining an improved efficiency.